Game Changers are cards that dramatically warp a game when (or shortly after) they're played
It does have an emphasis on creature-centric decks, but most green builds--including enchantments and especially modified--will have no shortage of creatures on the field
Overall, it can see play in the right context, but its effectiveness may depend on the specific metagame and deck composition
So, if you think The One Ring is a better choice, that's fine, Frodo
Mangara, the Diplomat : A consistent card draw mechanic in white that either dissuades opponents' actions or rewards you with card draw
Nowadays though, he primarily plays Legacy, his favorite format, but he also branches out into Pioneer and Modern